Introduction
The human retina is a thin tissue composed of neural cells that is located in the posterior portion of the eye. Because of the complex structure of the capillaries that supply the retina with blood, each person's retina is unique. The network of blood vessels in the retina is so complex that even identical twins do not share a similar pattern.
Although retinal patterns may be altered in cases of diabetes, glaucoma or retinal degenerative disorders, the retina typically remains unchanged from birth until death. Due to its unique and unchanging nature, the retina appears to be the most precise and reliable biometric.[1] Advocates of retinal scanning have concluded that it is so accurate that its error rate is estimated to be only one in a million.
A biometric identifier known as a retinal scan is used to map the unique patterns of a person's retina. The blood vessels within the retina absorb light more readily than the surrounding tissue and are easily identified with appropriate lighting. A retinal scan is performed by casting an unperceived beam of low-energy infrared light into a person’s eye as they look through the scanner's eyepiece.
This beam of light traces a standardized path on the retina. Because retinal blood vessels are more absorbent of this light than the rest of the eye, the amount of reflection varies during the scan. The pattern of variations is converted to computer code and stored in a database.[2]
History
The idea for retinal identification was first conceived by Dr. Carleton Simon and Dr. Isadore Goldstein and was published in the New York State Journal of Medicine in 1935.[3] The idea was a little before its time, but once technology caught up, the concept for a retinal scanning device emerged in 1975. In 1976, Robert "Buzz" Hill formed a corporation named EyeDentify, Inc., and made a full-time effort to research and develop such a device. In 1978, specific means for a retinal scanner was patented, followed by a commercial model in 1981.[4]
In popular culture
In the movie 'The Minority Report', retinal scanning is used everywhere to identify people. They are also used by the police in the movie to locate individuals throughout Washington, D.C.
In the 1982 movie "Star Trek: The Wrath of Khan", Admiral Kirk gains access to top secret computer files by use of a retinal scan.
In the 1966 movie Batman, Batman describes to Robin how the tiny vessels in the retina are unique to the individual and utilizing the portable retina scan device in the Batmobile they could confirm the identity of the Penguin.
Characters in the 1996 film Mission: Impossible, the film Paycheck, the 1995 film GoldenEye, and the 1999 film Entrapment utilize or try to deceive retinal scanners.[5]
In the 'Splinter Cell' series, retinal scanners are used to identify agents within Third Echleon and guards within military/business complexes.
How does retina biometrics work
Retina scans require that the person removes their glasses, place their eye close to the scanner, stare at a specific point, and remain still, and focus on a specified location for approximately 10 to 15 seconds while the scan is completed. A retinal scan involves the use of a low-intensity coherent light source, which is projected onto the retina to illuminate the blood vessels which are then photographed and analysed. A coupler is used to read the blood vessel patterns.
A retina scan cannot be faked as it is currently impossible to forge a human retina. Furthermore, the retina of a deceased person decays too rapidly to be used to deceive a retinal scan.
A retinal scan has an error rate of 1 in 10,000,000, compared to fingerprint identification error being sometimes as high as 1 in 500.
Uses
Retinal scanners are typically used for authentication and identification purposes. Retinal scanning has been utilized by several government agencies including the FBI, CIA, and NASA. However, in recent years, retinal scanning has become more commercially popular. Retinal scanning has been used in prisons, for ATM identity verification and the prevention of welfare fraud.[6]Retinal scanning also has medical application. Communicable illnesses such as AIDS, syphilis, malaria, chicken pox and Lyme disease as well as hereditary diseases like leukemia, lymphoma, andsickle cell anemia impact the eyes. Pregnancy also affects the eyes.
Likewise, indications of chronic health conditions such as congestive heart failure, atherosclerosis, and cholesterol issues first appear in the eyes.[7]
Pros and Cons
Advantages
Disadvantages
· Measurement accuracy can be affected by a disease such as cataracts
· Measurement accuracy can also be affected by severe astigmatism
· Scanning procedure is perceived by some as invasive
· Not very user friendly
· Measurement accuracy can be affected by a disease such as cataracts
· Measurement accuracy can also be affected by severe astigmatism
· Scanning procedure is perceived by some as invasive
· Not very user friendly
· Subject being scanned must be close to the camera optics
· High equipment costs
DOWNSIDE OF RETINAL SCAN
Unfortunately, there are also quite a few disadvantages to retina scanning. In many cases, people feel that the disadvantages of retina scanning outweigh any benefits. It is also the reason why retina scantechnology has mainly been used for high-risk security places, where it is believed the extra security provided by the retina scanner is needed.
If you're looking to make a large investment in high-end security, iris scans are probably a smarter move than retinal scans. With world-governments now choosing iris recognition over retinal scans, it's easy to see where the smart money is in high-end biometrics.
Currently, retinal scanners cost more than the vast majority of people or businesses can afford and are attended by similarly expensive subscription fees.
Other pitfalls include the risk that with so much invested in the scanner technology, it may cease to work for any one of its users as a result of any number of eye conditions. If any user was to develop cataracts or astigmatism there would be no way of altering the scanner to accommodate them.
The technology itself is also notoriously finicky. Retinal scanners are apt to malfunction in places with bright or inconsistent lighting, which could in turn lead to you forking over more money for new lighting arrangements.
CONCLUSION
